Civil Engineering Reference
In-Depth Information
energy generation technologies, their utility and the efficiency; in other analyses as
well.
The renewable energy technologies were assessed based on several critical
sustainability indicators. The selected indicators were price of generated elec-
tricity, GHG emissions during the full life cycle of the technology, availability of
renewable sources, efficiency of energy conversion and social impacts. Each
indicator was assumed to have equal importance to sustainable development and
used to rank the renewable energy technologies against their impacts.
The expert assessment of the effect of environmental factors on the value of
energy generation technologies has shown that such technologies must be analysed
from a much broader perspective than just their technical or economic properties.
5 Case Study 2: Energy Efficient House DSS for Cooling
A building design based on energy-saving criteria reduces economic costs
throughout the useful life of the building because of its lower energy consumption,
and this more than compensates for the greater initial investment. Since there are
also fewer CO
2
emissions into the atmosphere throughout the building's life cycle,
this benefits society as well (Pacheco et al.
2012
).
This is the reason, why the early stage building design and the use of optimi-
zation tools here are highly important. The building should be optimized according
to not only quantitative (energetic, environmental, economic), but also qualitative
(aesthetics, comfort) criteria.
As they start planning to build a house, clients often face a problem: how to
choose the best wall structures and windows, or how, in countries with hot cli-
mates, to keep more heat out. Not less important are the climate change factors,
due to structure materials or fuels used. We, therefore, develop an Energy Efficient
House DSS for Cooling that will make it possible to pick, by quantitative and
qualitative criteria, the best option from a range of available alternatives. It is a
universal system and the example discussed below is, therefore, tailored specifi-
cally for Johannesburg in South Africa.
To make proper assessment of the key properties of building envelope, all
decisions were based on actual estimates done with Swegon's Proclim. The
example in question is a model of a single-zone building (7 9 5 9 2.6 m) with all
its walls external; the window-to-wall ratio (WWR%) in the main façade makes up
10 %. The walls have the same properties as ''Exterior Wall 1'', the glazing has
the same properties as ''Glazing 1''. The main façade (with glazing) looks north.
This model is used as a reference in comparisons of alternatives. Johannesburg, a
city in South Africa, has been picked from the Climate Data Library. All walls
have their properties complying with South African National Standard (SANS)
204:2010, energy efficiency in buildings. The assessment trends of insulation
criteria (both of walls and windows) and glazing criteria in our system conform to
